Your browser doesn't support javascript.
loading
Phosphate esters in amylopectin clusters of potato tuber starch.
Wikman, Jeanette; Larsen, Flemming Hofmann; Motawia, Mohammed Saddik; Blennow, Andreas; Bertoft, Eric.
Afiliação
  • Wikman J; Department of Biosciences, Åbo Akademi University, Artillerigatan 6, FI-20520 Turku, Finland. jeanette.wikman@abo.fi
Int J Biol Macromol ; 48(4): 639-49, 2011 May 01.
Article em En | MEDLINE | ID: mdl-21335027
Starch phosphate is important in starch metabolism and in order to deduce its location and structural effects in clusters and building blocks of amylopectin, these were isolated from a normal potato (WT) and two starches with antisense suppressed glucan water dikinase (asGWD) activity and starch branching enzyme (asSBE) activity possessing suppressed and increased phosphate contents, respectively. Neutral N-chains and phosphorylated P-chains of the amylopectin macromolecules were similar in WT and asGWD, whereas asSBE possessed considerably longer P-chains. Cluster ß-limit dextrins were isolated by α-amylase treatment and successive ß-amylolysis. Cluster sizes were generally smaller in asSBE. The building block composition of neutral N-clusters were very similar in WT and asGWD, while asSBE was different, containing less blocks with degree of polymerization (DP)>14. Phosphate content of the P-clusters of WT and asGWD was rather similar, while asSBE contained highly phosphorylated P-clusters with proportionally more P-chains and a low degree of branching. The average chain lengths of the P-clusters were, however, similar in all samples. Our data demonstrate only minor effect on the cluster structure in relation to phosphate deposition suggesting conserved reaction patterns of starch phosphorylation. Models are suggested to account for the principle structural and functional effects of starch phosphate esters.
Assuntos

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Fosfatos / Amido / Solanum tuberosum / Tubérculos / Ésteres / Amilopectina Idioma: En Revista: Int J Biol Macromol Ano de publicação: 2011 Tipo de documento: Article País de afiliação: Finlândia

Texto completo: 1 Base de dados: MEDLINE Assunto principal: Fosfatos / Amido / Solanum tuberosum / Tubérculos / Ésteres / Amilopectina Idioma: En Revista: Int J Biol Macromol Ano de publicação: 2011 Tipo de documento: Article País de afiliação: Finlândia